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Shear strength of the fiber-reinforced polymer composite
Jurko, Michal ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
The diploma thesis deals with the study of Inter-Laminar Shear Strength (ILSS) of polymer composites, based on unsaturated polyester resin with unidirectionally oriented basalt or glass fibers. The basis of the experimental part is the preparation of composite samples with different types of surface treatment of a fibers (a reinforcement) as well as the surface treatment itself. The untreated, the commercially treated fibers and the plasmatreated fibers used as reinforcement in the polymer composites were analysed by a short beam shear test and their ILSS was determined. The effect of various deposition conditions during Plasma-Enhanced Chemical Vapour Deposition (PECVD) on the value of ILSS of the composite with originally unsized glass or basalt fibers was studied. The impact of aging on the interlaminar shear strength of the composites was investigated for commercially treated glass fibers. The Scanning Electron Microscopy (SEM) is also used in the thesis together with the Energy Dispersive Spectroscopy (EDS). Based on all the results a proposal was made to correct and improve the deposition conditions and thus improve the interphase to achieve the required shear properties of polymer composites.
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Pathological consequences of hypokinesis in paraplegic patient and their identification by TVS method
Vavrová, Dominika ; Jelen, Karel (advisor) ; Čichoň, Rostislav (referee)
Thesis title: Pathological consequences of hypokinesis in paraplegic patient and their identification by TVS method The thesis focus: The focus of the thesis was to identify and classify differences of mechanical properties of axial systems between paraplegic patient and people from healthy population. Secondary focus of the thesis was to identify and classify changes of mechanical properties of axial system in paraplegic patient depending on physiotherapeutic intervention. The research methods: Three people, one paraplegic person and two healthy people were measured with TVS (Transfer Vibration Through Spine) method. Paraplegic person was measured twice, before and after one hour long physiotherapeutic intervention (PI). Healthy people were measured once, without PI. TVS method is a diagnostic apparatus that enables qualitative and quantitative classification of properties of axial skeleton and its segments. It is based on fact that velocity of mechanical waves and density of mechanical energy transmitting through axial skeleton is affected by properties of this system. Thus we were able to analyze and identify mechanical properties of measured axial systems according to differences of input and output values of acceleration on particular spinous processes. The results: When we compared frequency...
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Detection of rheological changes in the axial system of pregnant women using the TVS method.
Plačková, Veronika ; Jelen, Karel (advisor) ; Šorfová, Monika (referee)
Title: Detection of rheological changes in the axial system of pregnant women using the TVS method. Objectives: The aim of this thesis is to evaluace the effect of pregnancy on the biomechanical properties of the spine. Methods: TVS vibration diagnostic methods were applied to six pregnant women twice during pregnancy. It was investigated ability of axial system to dampen vibration spreading through out the spine. The ability of every single segment to damp vibrations were compared with each other at the beginning and during pregnancy. Results: TVS method used for purpose of this paper has been proved adequate to provide information about the resonant frequencies and the total attenuation of the spine with sufficient accuracy, so that the biomechanice changes of axial system during pregnancy could be decidly identified. Comparison of the frequency dependency and total attenuation of spine indicated increase of total attenuation of the spine and also increase of flexibility of the spine in all investigated probands. Keywords: gravidity, pregnancy, axial system, vibrations, TVS, spine
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Shear strength of the fiber-reinforced polymer composite
Jurko, Michal ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
The diploma thesis deals with the study of Inter-Laminar Shear Strength (ILSS) of polymer composites, based on unsaturated polyester resin with unidirectionally oriented basalt or glass fibers. The basis of the experimental part is the preparation of composite samples with different types of surface treatment of a fibers (a reinforcement) as well as the surface treatment itself. The untreated, the commercially treated fibers and the plasmatreated fibers used as reinforcement in the polymer composites were analysed by a short beam shear test and their ILSS was determined. The effect of various deposition conditions during Plasma-Enhanced Chemical Vapour Deposition (PECVD) on the value of ILSS of the composite with originally unsized glass or basalt fibers was studied. The impact of aging on the interlaminar shear strength of the composites was investigated for commercially treated glass fibers. The Scanning Electron Microscopy (SEM) is also used in the thesis together with the Energy Dispersive Spectroscopy (EDS). Based on all the results a proposal was made to correct and improve the deposition conditions and thus improve the interphase to achieve the required shear properties of polymer composites.
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Detection of rheological changes in the axial system of pregnant women using the TVS method.
Plačková, Veronika ; Jelen, Karel (advisor) ; Šorfová, Monika (referee)
Title: Detection of rheological changes in the axial system of pregnant women using the TVS method. Objectives: The aim of this thesis is to evaluace the effect of pregnancy on the biomechanical properties of the spine. Methods: TVS vibration diagnostic methods were applied to six pregnant women twice during pregnancy. It was investigated ability of axial system to dampen vibration spreading through out the spine. The ability of every single segment to damp vibrations were compared with each other at the beginning and during pregnancy. Results: TVS method used for purpose of this paper has been proved adequate to provide information about the resonant frequencies and the total attenuation of the spine with sufficient accuracy, so that the biomechanice changes of axial system during pregnancy could be decidly identified. Comparison of the frequency dependency and total attenuation of spine indicated increase of total attenuation of the spine and also increase of flexibility of the spine in all investigated probands. Keywords: gravidity, pregnancy, axial system, vibrations, TVS, spine
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Pathological consequences of hypokinesis in paraplegic patient and their identification by TVS method
Vavrová, Dominika ; Jelen, Karel (advisor) ; Čichoň, Rostislav (referee)
Thesis title: Pathological consequences of hypokinesis in paraplegic patient and their identification by TVS method The thesis focus: The focus of the thesis was to identify and classify differences of mechanical properties of axial systems between paraplegic patient and people from healthy population. Secondary focus of the thesis was to identify and classify changes of mechanical properties of axial system in paraplegic patient depending on physiotherapeutic intervention. The research methods: Three people, one paraplegic person and two healthy people were measured with TVS (Transfer Vibration Through Spine) method. Paraplegic person was measured twice, before and after one hour long physiotherapeutic intervention (PI). Healthy people were measured once, without PI. TVS method is a diagnostic apparatus that enables qualitative and quantitative classification of properties of axial skeleton and its segments. It is based on fact that velocity of mechanical waves and density of mechanical energy transmitting through axial skeleton is affected by properties of this system. Thus we were able to analyze and identify mechanical properties of measured axial systems according to differences of input and output values of acceleration on particular spinous processes. The results: When we compared frequency...
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